however, a fuel cell does not run down or require recharging. It will produce energy in the form of electricity and heat as long as fuel is supplied. Since the fuel cell relies on chemistry and not combustion, emissions are much lower than from the most efficient internal combustion engines, and consist primarily of water and steam. (http://www.ethanolrfa.org/fuelcells.htm)
The co-products that results when making ethanol are dependent on the medium used to produce the ethanol. Table 2 shows a summary of the co-products and what they are used for.
In practice, about two-thirds of each tonne of grain (i.e., the starch) is converted to ethanol. The remaining by-product is a high protein livestock feed which is particularly well suited for ruminant animals such as cattle and sheep. This by- product is also known as Distillers' Dried Grains, DDGS. The protein in this material is utilized more efficiently in ruminant nutrition than are other high-protein feed ingredients such as soybean meal. This by-product of ethanol production is particularly good for Canadian dairy, beef and sheep production. It improves the competitive position globally of producers of these farm commodities. The manure from livestock can be used as a major source of fertilizer in grain crop production. (http://www.greenfuels.org/ethafood.html)
Carbon dioxide is another of the by-products produced when making ethanol. Carbon dioxide, given off in great quantities during fermentation will be collected and cleaned of any residual alcohol, compressed and sold as an industrial commodity. (http://www.comalc.com/chatham.htm)
Table 2: Summary of by-products/co-p by-products/co-products
roducts made through ethanol production. Used for
Flour, Corn Oil, Corn Meal, Corn Grits FibroteinTM Corn Gluten Meal and Corn Gluten Feed Amino Acids Dry Distiller's Grains Carbon Dioxide
Used in producing food for human consumption Used as a high fibre and protein food additive Used as high protein animal feed additives Used as animal feed additives Used as high protein and energy animal feed Used as a refrigerant, in carbonated beverages, to help vegetable crops grow more rapidly in greenhouses, and to flush oil wells
The Economics of Ethanol
There are many benefits to the economy when building, producing and selling ethanol. These are discussed in the following sections.